In recent years, larger capacities of data and faster speed of communications in computer network communications have been desired. Here, in data processing on a network, performance of inter-device communication of server devices supporting data communications has been a bottle neck. In the server device, a plurality of boards are connected to a printed circuit board, called backplane, to which a connector and a slot provided in a chassis of the server device are attached. In data communication in the server device, transfer and reception of signals are performed between boards via the backplane. In this situation, a distance for the signals to be transferred is about 20 cm to 100 cm, and the longer the transferred distance, the larger a distortion of signal waveforms to flow on the backplane, making it difficult to accurately transfer signals. To solve this problem, a signal processing technology for accurately correcting distorted signal waveforms has been studied. Particularly, technology, called FFE (Feed Forward Equalization), of transmitting waveforms distorted in an opposite direction from a transferring side while predicting a distortion of a signal waveform is effective and generally used as described in Japanese Patent Application Laid-Open Publication No. 2007-209030.